1. Field of the Invention
The present invention relates, generally, to apparatus and methods used in the packaging industry. More particularly, the invention relates to means for successfully loading articles into optimally sized cartons. Specifically, the invention relates to means for maintaining the relatively rectangular dimensions of carton sleeves and opening the ends of carton sleeves to permit the loading of articles into optimally sized cartons. The invention has particular utility in re-opening the bowed ends of partially erected paperboard carton sleeves in continuous motion cartoner assemblies. However, the invention also may have utility in other applications.
2. Background Information
In the past, various devices and methods have been used or proposed to load article groups into carton or other packaging sleeves, blanks or wraps in a cartoner or other packaging machine. However, these devices and methods are believed to have significant limitations and shortcomings. One problem is that cartoners are periodically stopped for maintenance, product changeovers, and other reasons. After a period of idle time on a cartoner assembly, partially erected carton sleeves, particularly those constructed of paperboard, have a tendency to lean or skew from their rectangular dimensions, and the flaps of the sleeves have tendency to bow. Both the skewed carton sleeves and bowed flaps interfere with the loading of article groups. The bowed flaps can be erroneously pushed and folded into the carton with the article groups. The side walls of the skewed carton sleeves may prevent or interfere with the loading of article groups into cartons, particularly those that are optimally sized. Optimally sized cartons have dimensions that are only very slightly larger than those of the article group to be loaded so as to be taut, square, stable and so as to minimize material usage.
Examples of cartoners upon which the device of the present invention may be used are described in U.S. Provisional Application 60/016,930 (hereinafter referred to as "Provisional Application '930"), U.S. Pat. No. 5,456,058 (hereinafter referred to as "Patent '058"), and U.S. Pat. No. 5,241,806 (hereinafter referred to as "Patent '806"). Provisional Application '930, Patent '058, and Patent '806 are all assigned to applicants' assignee and are all hereby incorporated by reference.
Provisional Application '930 discloses an article group transfer mechanism constructed and arranged to move stacked article groups into open ends of carton sleeves. The mechanism is incorporated in a continuous motion cartoner assembly and is used to transfer stacked bottles into carton sleeves. In a preferred embodiment, the transfer apparatus includes a plurality of transfer elements, means for longitudinally moving the transfer elements, and a cam track assembly. The plurality of transfer elements are disposed at predetermined longitudinally spaced intervals. The transfer elements laterally move articles which are being longitudinally transported in a stream. Each transfer element includes a lower contact member and an upper stepped contact member, a support member connected to the contact members, and a control member for directing the lateral movement of the transfer elements. The control member of the transfer element includes a first cam follower connected to the support member controlling lateral movement of the transfer elements, and a second cam follower pivotally connected to the support member and connected to the contact member via linkage means. The second cam follower of the control member provides differential lateral movement between the upper and lower contact members. A third cam follower of the control member is pivotally connected to the support member and is connected to the contact member via linkage means. The third cam follower provides differential lateral movement to predetermined portions of the stepped contact member. The transfer apparatus further includes means for longitudinally moving the transfer elements, said means being connected to the support member. The transfer apparatus also includes a cam track assembly capable of laterally moving the transfer elements. The cam track assembly is cooperatively mated with the first and second cam followers.
Patent '058 discloses a continuous motion cartoner assembly for loading stacked or vertically layered article groups into cartons. This device is used to load stacked cans into carton sleeves. The cartoner assembly comprises an article infeed mechanism supplying at least two streams of articles at vertically distinct levels; an article group selection and transport mechanism intersecting the article infeed mechanism to form a longitudinal stream of article groups of a predetermined stacked pattern; a carton supply and transport mechanism synchronized and moving parallel with the article group selection and transport mechanism to provide cartons with open ends facing the moving article groups; and an article group transfer mechanism constructed and arranged to move the article groups into the open ends of the carton sleeves. This cartoner provides a method of continuously loading cartons with stacked article groups having upper and lower sub-groups of at least one article. The method comprises the steps of supplying an input stream of articles at a first location, selecting articles at the first location to form a lower article sub-group, transporting the lower article sub-groups longitudinally to a second location, supplying an input stream of articles at the second location, selecting articles at the second location to form an upper article sub-group on top of the lower article sub-group to thereby form a stacked article group, supplying and longitudinally transporting a carton in spacial synchronization with the stacked article group, and laterally transferring the stacked article group into the longitudinally transported carton.
Patent '806 discloses a cartoner assembly for loading article groups into open carton sleeves. It is used to load unstacked bottles or cans to carton sleeves. The cartoner assembly comprises an article infeed mechanism supplying at least one stream of articles, an article selection mechanism intersecting said article infeed mechanism to form and move a stream of article groups of a predetermined pattern, a carton transport mechanism synchronized and moving parallel with said article selecting mechanism to provide cartons with open ends facing said moving article groups, and an article groups transfer mechanism constructed and arranged to move article groups into the open ends of the carton sleeves. The article selection mechanism has a plurality of fixed, stationary flight bars disposed thereon which linearly select articles from the article infeed mechanism which is angled with respect to the article selection mechanism The article groups transfer mechanism has transversely reciprocating arm assemblies, including cam actuated stepped transfer heads, for loading product groups in an initially nested configuration having a differentially thinner loading dimension. The article groups transfer mechanism includes cam actuated means to guide product groups into cartons. The carton transport mechanism has improved carton flight phase adjustment means.
Despite the need in the art for a continuous motion carton assembly which overcomes the disadvantages, shortcomings and imitations of the known art, none insofar as is known has been developed. Accordingly, it is an object of the present invention to provide a cartoner that successfully loads article groups in optimally sized, taut paperboard cartons upon machine start-up after a period of idle time. Another object is to provide a mechanism that will reliably maintain the relatively rectangular dimensions of cartons sleeves and open or re-open the bowed flaps of the carton sleeves during machine operation prior to the loading of the articles into the carton sleeves.